You'll need to do some testing, there's no way around it. In our experience there's not a huge difference between the H/W and the Sport Tuned on most tracks.
And I suspect the same would be the case for the other motors that you're using. In fact I'd bet that if you allowed the H/W's, within 6 months everyone would switch to them anyway. That's certainly been our experience.
I repeat what I've said before - It's THE best thing we ever did for Mini racing down under, without question.